In medical imaging, for example during a treatment of a patient, interfaces for user interaction are provided. For example, footswitches are provided in order to activate X-ray imaging. Further, manually operable user interfaces, such as table side modules, are provided for the physician to activate navigation tools. For example, in case of coronary artery syndrome treatments, where X-ray imaging is used for diagnosing, navigating and treating a coronary stenosis, a physician is assisted in navigation of a guide wire through a diseased coronary artery. For example, a previously recorded angiogram can be overlaid, providing cardiac roadmapping overlaid onto a life fluoroscopy image that only shows the guide wire and its radiopaque tip. The table side module may be attached to the patient table and provides a touchscreen with buttons and messages guiding the physician through the use of the application. However, the need to press or activate buttons on a screen may be cumbersome due to the limited range of reach of the physician's arm. US 2011/0060423 A1 describes automatic activation and deactivation of a radiation source for medical purposes and describes an observation whether the eyes of the user face a point of reference or not, thus ensuring that X-ray radiation is only provided on purpose. The user is provided with a receiver or emitter, and the monitor is provided with the respective counterpart emitter or receiver, such that a signal is only generated when the operator is looking at the monitor or in the appropriate direction.